The purpose of this project is the purification and characterization of placental enzymes, pregnancy-associated enzymes in maternal plasma, and fetal enzymes. Topics of current interest are: (1) the induction in choriocarcinoma cells of placental alkaline phosphatase, an enzyme which appears in maternal serum during pregnancy and which is one of the ectopically produced proteins seen in certain patients with malignant neoplasms; (2) the phosphoprotein phosphatase activity exhibited by placental alkaline phosphatase; (3) the regulation of glycogen synthesis in human placenta and choriocarcinoma cells through phosphorylation and dephosphorylation reactions involving glycogen synthetase, phosphorylase, and various protein kinases and phosphoprotein phosphatases; (4) the elucidation of the enzyme reactions involved in lysine metabolism and of the relationship of these enyzmes to the metabolic defects and clinical manifestations of hyperlysinemia, saccharopinuria, alpha-aminoadipic aciduria, and glutaric aciduria.